The French woman targeted in a racist attack on a Melbourne bus earlier this month says she and her friends were terrified they would be physically assaulted by a group of fellow passengers.

It comes as police confirm they are investigating the tirade unleashed on Fanny Desaintjores aboard a bus travelling between Mordialloc and Caulfield, in which she was called a c---, a dog and threatened with having her breasts cut off after she sang a song in her native tongue.

Ms Desaintjores told Fairfax Media she and about nine friends were on the bus, having spent the day at the beach for a barbecue and enjoying the weather.

Fanny Desaintjores, inset, with the man who abused her aboard the bus. Photo: YouTube

"I thought he was kind of joking at first and then I realised he wasn't kidding at all, so my friends and I stopped laughing. We were quite afraid that he [would come] and hit us."

A couple, a woman and a man, pushing a pram, also joined in. The man shouted: "I'll f---ing boxcutter you right now, dog."

Ms Desaintjores said that when the couple got off the bus, the man smashed a window close to them and glass fragments hit her and a friend.

"At this point, I was really scared," she said.

My friends and I stopped laughing. We were quite afraid that he [would come] and hit us.

"I realise that maybe we shouldn't sing in a public transport, but I think that's insane that they reacted like that, we're all adults. We could have a conversation and talk gently, instead of all these insults and threats."

The incident was reported to police on Wednesday after video footage of the incident went viral.

She was abused and called a c---, a dog, a bitch and, after singing in French, was told to "speak English or die motherf---er".

Police are looking for the two men and the woman. Anyone with information about the incident, or who was on the bus, is asked to phone CrimeStoppers on 1800 333 000.